How to replace bar end

[kongjie]

From when I got my bike the right bar end spun loosely; I couldn't tighten it up, and I wasn't sure how to extract it to take a look at it.

Finally the other day I guess it dropped off while I was riding. Not sure how I missed it, but I'm left with this:
[attachment=1:2mudkx1x]missing_bar_end.jpeg[/attachment:2mudkx1x]

I bought a replacement bar end, so I have this:
[attachment=0:2mudkx1x]bar_end.jpeg[/attachment:2mudkx1x]

The question is, of course, how do I get the old one out? Presumably, because I couldn't tighten up the old one, the nut must have come off the end of the bolt, so I can't screw in the new bolt and go that way. Should I cut the rubber out? Or stick in a hanger and try to yank it out?